Introduction: Understanding childhood obesity becomes vital as a tremendous increase in the prevalence of over- weight/obesity among children and adolescents was observed. This cross-sectional study aimed to investigate the as- sociations between sociodemographic and psychological characteristics with body-mass-index-for-age (BAZ) among adolescents in Sibu, Sarawak. Methods: A total of 375 students (32.0% males and 68.0% females; 15-17 years old) at four randomly selected public secondary schools were recruited. A questionnaire on sociodemographic and psycho- logical characteristics (self-efficacy for physical activity, weight management, and nutrition, body discrepancy score, and sociocultural pressure to be thin) were used to gather information. Body weight and height were also assessed. Results: Around 18.6% respondents were found to be overweight/obese while nearly 5.0% were categorized as thin. In multiple linear regression, three significant predictors, namely body discrepancy score, being Iban (Reference: Chinese) and sociocultural pressure to be thin explained 45.1% of the variance in BMI-for-age z-score. Conclusion: Future interventions on adolescent body weight management should consider incorporating sociodemographic and psychological factors such as the development of positive body image, uniqueness in cultural value, and manage- ment of perceived sociocultural pressures to increase their effectiveness.